Preheat the oven to 160ºC/320ºF. Sift flour and baking powder together and set aside.
Place the butter, sugar and vanilla in the bowl of an electric mixer and beat for 8-10 minutes, until light and creamy. Gradually add the eggs, beating well after each addition. Add the flour and baking powder, alternating with the milk, and beat until the mixture forms a smooth batter.
Spoon the mixture into ¼ cup capacity muffin tins lined with patty cases to ¾ full. Bake for 18-20 minutes – mine needed 30 – or until golden. Cool on a wire rack.
To make the icing, place the sugar, water and food coloring in a bowl and mix until smooth. Use a palette knife to spread the icing over the cupcakes.
Place 1-2 violets over each cupcake.